While filming, Bernardo Bertolucci tried to explain the point of the film to Marlon Brando, suggesting that his character was Bertolucci's "manhood" and that Maria Schneider's character was his "dream girl". Brando later maintained that he had absolutely no idea of what Bertolucci was suggesting or even talking about.
According to Maria Schneider, the famous "butter scene" was never in the script and improvised at the last minute by Marlon Brando and Bernardo Bertolucci without consulting her. Though the sodomy act was faked, her real tears in the film clearly testify her state of shock.
When Marlon Brando arrived for the first day of shooting, he had on makeup "two centimeters thick" according to Bernardo Bertolucci. Brando, who had applied his own makeup, didn't understand the natural, low-light conditions cinematographer Vittorio Storaro was going to work with to get the look of the film. Bertolucci had to remove much of the makeup from Brando's face with a handkerchief.
The idea of this movie grew from Bernardo Bertolucci's own sexual fantasies, stating that "he once dreamed of seeing a beautiful nameless woman on the street and having sex with her without ever knowing who she was".
After the film's release in Europe, director Bernardo Bertolucci, producer Alberto Grimaldi, Marlon Brando and Maria Schneider were all indicted by a court in Bologna, Italy for making the film under the term "ultalitarian pornography". They were all acquitted of the charge shortly thereafter with Bertolucci losing his civil rights (including his right to vote) for five years.
Jean-Pierre Léaud had so much respect for Marlon Brando that he was afraid to meet him. That's why he shot all his scenes on Saturdays, when Brando refused to work. Due to this, the two never met in the entire making of the film on and off screen.
The story Paul tells Jeanne about his mother, about how she taught him to appreciate nature, which he illustrates with his reminiscence of his dog Dutchy hunting rabbits in a mustard field, is real, based on Marlon Brando's own recollections of his past.
When Paul puts on the Colonel's kepi (the French military hat that had belonged to Jeanne's father) and says to her, "How do you like your hero? Over easy or sunny side up?"; Marlon Brando - the author of most of the film's English dialog - is using egg imagery because the gold braid on an officer's hat is referred to as "scrambled eggs" in the U.S. military. Brando attended Shattuck Military Academy (from which he was booted out) and failed his physical for the U.S. Army during World War Two due to a bum knee hurt playing high school football.
Argentine Tango composer Astor Piazzolla was going to write the music for the film and had actually submitted demos to director Bernardo Bertolucci. Bertolucci instead chose famed jazz musician Gato Barbieri as the film's composer because he felt that his saxophone playing would give the film a more rich and sultry feel for the film.
Almost ten years after its original release, United Artists re-released the film in 1982 with an R-Rating and not the infamous X rating it had obtained in 1972. The film was only a couple of minutes shorter than the preferred Director's cut.
In protest against the film only receiving a minor cinema cut in the UK, a private prosecution was brought against United Artists in January 1974 by 69 year old Edward Shackleton, a Salvation Army member and leading member of the executive committee of the pro-censorship Festival Of Light party. Although the case went as far as the Old Bailey it collapsed when it was ruled that the Obscene Publications Act did not, at that time, apply to films.
Created considerable controversy in Canada. The Ontario Board of Film Censors passed a cut version of the film to be shown in theaters. Upon release, the board received over one hundred complaints from the public from the Toronto area alone. In Nova Scotia, the film was rejected outright and the film board attempted to lay obscenity charges on the distributor.
Such was the controversy over the film that the print was smuggled into the USA for its debut in a diplomatic pouch from Italy. The film was due to have its premiere at the New York Film Festival where tickets were going for $150.